Lilac

SYRINGA

MANY YEARS AGO I READ A CHARMING BOOK TITLED ELIZABETH AND HER GERMAN GARDEN, PUBLISHED IN 1898. IT WAS A MEMOIR BY ELIZABETH VON ARNIM, AN ENGLISHWOMAN WHO IN THE LATTER PART OF THE NINETEENTH CENTURY MOVED WITH HER HUSBAND TO HIS FAMILY’S LANDS IN POTSDAM, GERMANY. THE BOOK AND ITS DESCRIPTIONS OF HER ASTONISHING GARDENS REKINDLED MEMORIES OF THE GARDENS I DREAMED ABOUT WHILE GROWING UP.

It was as if Elizabeth and I had had the same dreams as children—those of light and air and vast expanses of romantic plantings, intoxicatingly scented and delicately colored. Elizabeth had a lilac hill that seemed to stretch endlessly through space. The lilacs that grew around and near my childhood house were most certainly the old-fashioned Syringa vulgaris. Beautifully colored and perfumed, they were common in our neighborhood but very special to me. One of my favorite Greek myths was the story of the god Pan who pursued the nymph Syrinx and turned her into a hollow reed from which he fashioned his first flute, or “panpipe.” An early name for the lilac was pipe tree or blow stem. This identification of the tree with a musical instrument and a legend was what growing up for me was all about: literature and gardening and learning and experiencing.

I married in 1961, and on our car trips throughout the Northeast I tried to schedule visits for the time of year when lilacs would be in bloom. The Arnold Arboretum in Massachusetts was a treasure trove of older varieties. The area in and around Rochester’s Highland Park neighborhood, designed by Frederick Law Olmsted, is filled with vast numbers of the shrubs in spectacular colors. When I lived in Manhattan, I would visit my sister-in-law in Bedford, New York, during lilac time to pick to my heart’s content. It was then that I vowed to always have great numbers of these productive and dependable shrubs growing wherever I lived. When, as a young couple, we purchased our home in Westport, Connecticut, I was thrilled by the large clumps of lilac shrubs that seemed to be growing everywhere. You can imagine my utter dismay when in spring the leaves grew no larger than a privet’s leaves. Indeed that is what all the shrubs were—very overgrown privets. It took several years before the tiny hybrid shrubs I ordered from catalogs matured to flower-bearing size. Many years later, there were plenty of fragrant flowers at Turkey Hill in May and June.

And every year, I added to my collection. When I moved to Katonah, I found myself back at square one as far as lilacs were concerned. There was not one of these outstanding shrubs on the 150 acres. So I collected and planted a sizable assortment in two long matching borders the length of the entire Maple Avenue house. Within three years, the display was very showy, and the numbers of blooms so exciting. Now some of the shrubs are actually bushy trees, 15 feet or so in height, and the lilacs range in color from white to deepest purple-black.

At Skylands, I planted one area of the vegetable garden with lilac shrubs I found at Surry Gardens in Surry, Maine. I planted them the second year I owned the house, and now, more than fifteen years later, I have an unusual and gorgeous array of well-flowering shrubs. How wonderful to anticipate need and desire, and then to fulfill both with the most amazing plants.

Lilacs look beautiful arranged by the armload with leaves as sole accompaniment. “I really like it when I can get the lilac foliage to live, but if I can’t do that, I like to use other types of foliage, especially smoke bush leaves,”Kevin says. In a French Art Deco painted cast-iron trumpet vase, he paired ‘Angel White’ and ‘Beauty of Moscow’ lilacs with smoke bush leaves, whose plum-brown shade perfectly complements the lilac’s pale lavender. “Foliage can really help to achieve the overall shape you’re aiming for, especially when the flowers don’t necessarily cooperate.”

There are more than four hundred varieties of Syringa vulgaris alone, in a range of colors, fragrances, and sizes. We grow many of them at the farm in Katonah, such as the bicolor ‘Sensation’ pictured here. Their cold-hardiness makes them a natural in Maine as well, where we harvest armloads of lilacs every spring.

GROWING & ARRANGING

THE COMMON LILAC (SYRINGA) HAS BEEN A BELOVED PART OF THE AMERICAN LANDSCAPE FOR CENTURIES; THE FLOWERS ARE SWEETLY FRAGRANT AND COLORFUL. WHEN GIVEN PLENTY OF SUN AND WELL-DRAINED SOIL, THEY ARE INCREDIBLY STURDY AND UNDEMANDING—AND BOUND TO THRIVE AND DELIGHT.

Lilacs, such as Katonah’s ‘Firmament’, bloom for only about two weeks in spring, but the plants themselves—which can grow up to 15 feet tall—can live a very long time. Some have survived more than a century. That longevity requires tender loving care, of course, including a good amount of sun and water, and regular pruning in late spring and early summer, just after the blooms have finished.

When the lilacs are in full bloom in Katonah, the air is filled with their sweet scent. Because of my lifelong love of lilacs, I grow many, many varieties, and when they’re ready to be cut, we need more than a wicker flower basket to gather them for arrangements. Some of the varieties include ‘Wedgwood Blue’, ‘President Poincare’, ‘Little Boy Blue’, ‘Atheline Wilbur’, ‘Paul Thirion’, ‘Sensation’, ‘Angel White’, and ‘Adelaide Dunbar’. After carefully cutting them, we fill up the bed of the Kawasaki Mule to transport them through the linden allée and back to the house for prepping and arranging.

HOW TO GROW

Lilacs thrive in their native climate of somewhat chilly, mountainous regions. Though heat can be their undoing, nurseries have bred hybrids that can handle warmer zones—even in the dry heat of Texas. The Syringa x laciniata, with its elegant, fine-textured foliage, can also fare well in warmer areas, even after its pale-lavender flowers have faded.

ZONE Lilac shrubs grow in cooler climates with chilling periods, Zones 4 to 7, and bloom for just two weeks in late spring and early summer. In order to flower, it’s essential for common lilacs to experience a proper winter chill. Without one, they struggle and bloom irregularly; some don’t flower at all. If you live in a location that has mild winters (Zones 7 and 8), choose a Descanso hybrid (specifically bred for “no-chill” climates); some cultivars, such as ‘Blue Skies’, ‘Excel’, and ‘Sister Justina’, have been bred for even warmer regions (Zones 8 and 9).

SOIL Lilacs need well-drained soil that is rich in organic matter and fairly neutral in pH—slightly acidic or alkaline levels are fine. New England soils, including the soil on the farm at Katonah, are often very acidic and require some amendments to ensure proper lilac growth. We treat that soil with composted horse manure, superphosphate, and Azomite, a finely ground natural trace mineral powder made from sea bed clay that functions as both a fertilizer and soil remineralizer.

Lilacs need good drainage in order to thrive, so it’s crucial to check your soil before planting. It should retain enough moisture to thoroughly nourish the root system, but drain quickly. To test, dig a hole about 1 foot deep and 8 inches in diameter. Fill with water, and then check back in an hour. If the water has not drained, choose another site.

LIGHT In order to flourish, common lilacs need lots of sunshine, at least six to eight hours daily, ideally in the morning (when it’s not as hot). Lilacs grown in partial sun or shade will not flower well, and even a shrub planted in full sun years ago may now find itself shaded by larger trees that have grown around it. In this case, start with a new plant in a sunnier location.

CHOOSING Lilacs can be purchased in bare-root form, as a potted root-ball, or as a partially grown bush. Bare roots are dormant plants often sold or shipped in bags of moist sawdust or wood shavings, with a few bare twigs extending from the root clump. Bare-root stems should be about the thickness of a finger; avoid anything thin or brittle. Make sure the roots are intact and that the stems are fully dormant—they should be somewhat flexible and will reveal some green underneath if scratched with a fingernail. When selecting a potted bush or root-ball, carefully examine the root system to ensure it is healthy, and choose a plant with strong, even branches and no signs of disease. There should be no flowers on the plant; this indicates the plant is funneling all its energy into flower production rather than establishing a strong root system. If you remove the plant from the pot, the root-ball should come out intact; but if there are so many roots that they are circling the pot or growing out of the bottom, the plant has been potted for too long. Choose another.

PLANTING Early spring and fall are the best times to plant; many growers prefer to plant lilacs in fall, especially in milder climates. Dig a large hole that is two to three times as wide as the root-ball, and place the top of the root-ball level with the surface of the hole. If planting a bare root, the top layer of roots should sit a few inches below the surface. Fill in with soil and water thoroughly to stabilize the plant and guard against air pockets under the surface. In addition to selecting a spot that is large enough to accommodate the mature size of your lilac plant, choose one that has good air circulation to reduce the likelihood of developing fungal diseases such as powdery mildew.

Don’t expect blooms the first year—or even the second—and if any develop, cut them off to help the plant focus its energy into creating a strong root system (see Pruning, below). From the third year onward, blooming should be prolific. The common lilac is often considered the best-smelling variety and boasts the largest flowers, but its bloom time is short. Include other lilac species to double your blooming time—and you’ll sometimes see a bonus of repeat flowerings around Labor Day, as well.

WATERING Water young plants regularly at planting, during bloom, and in heavy growth periods. Once established, lilacs are fairly drought-tolerant. Aim for an inch of water per week, supplemented by you if your area doesn’t get enough rain, and water more frequently during bloom season—an inch twice a week instead of once, depending on your soil type and how the plant looks. After blooming ends, gradually cut back on watering, unless your area is experiencing unnaturally hot or dry weather.

FERTILIZING Fertilize lilacs early in the season with a balanced organic fertilizer. After pruning, use compost, composted manure, or a balanced chemical fertilizer, and ensure that the soil pH is close to neutral. These amendments and some good mulch will help to stimulate vigorous new growth and better flowering in years to come.

PRUNING Mature lilacs need pruning to promote flowering, to reshape, and to remove unwanted suckers (shoots that develop where the stem meets the ground; see Propagating, below). Don’t be shy with your clippers; lilacs are hardy and can withstand a lot of cutting, but timing is crucial. Almost immediately after blooming, the shrub begins to set buds for next season’s show. You should prune right after the blooms have faded, and never after the first week of July, or you risk losing future blossoms. To prune properly, cut any diseased, misshapen, and unproductive stems at or just below soil level. Remove the large, unattractive seedpods that form after flowers fade, and prune out any dead, damaged, or diseased branches as you see them, cutting just above a bud. Remove old, woody stems to encourage air circulation and increase exposure to sunlight; proper, yearly pruning can ensure reliable blooming for more than a decade. ‘Palibin Meyer’ (Syringa meyeri) and ‘Miss Kim Manchurian’ lilacs (Syringa pubescens ssp. patula), both of which we grow at Katonah, can be relatively small shrubs (under 8 feet) with a twiggy habit. Little pruning other than deadheading is required on these types.

PROPAGATING Lilacs are typically clump-forming, producing new shoots, or suckers, from the base of the trunk. Suckers can be unsightly and drain the shrub’s strength, so cut them off in order to funnel energy to the mother plant. Suckers can also be used to propagate new shrubs. Simply remove soil from the top of the roots, cut off suckers with pruning shears, and then replace the soil. Larger suckers can be dug up with their roots intact and grown in pots until they are large enough to be transplanted.

TROUBLESHOOTING If a lilac shrub doesn’t flower regularly, it could be due to lack of sun, poorly timed pruning, or your climate. Make sure to choose a variety suitable for your region’s hardiness zone. The most prevalent lilac problems are powdery mildew fungus, lilac borer, and scale (both oyster-shell scale and prunicola scale are common). Some lilac issues affect certain regions more than others—the foggy chill of San Francisco makes mildew more of a risk, while warmer regions of the South attract more insects, including aphids and scale. Powdery mildew appears in the form of white patches dusting the leaves, and, though unattractive, it is rarely serious. Borers leave ⅛-inch holes in stems and larger branches, often 1 to 2 feet above ground level. A minor infestation might be ignored, but a plant with more than a few borers should be attended to by a professional. Oyster-shell scale is aptly named, as the pests look like tiny oyster shells covering the stems, while prunicola scale covers bark with a dusty white mass. Control scale by pruning heavily infested branches; remove young “crawlers” with a hard spray of water from a garden hose. My lilacs are generally pest-free, so we rarely need to spray, but dormant oil would be my first choice if the need arose. Also known as summer oil, it’s a type of horticultural oil used to kill pests by smothering them. It is especially effective on aphids, scale, and mites. It was once only used during the dormant season, as the oil could burn foliage under the heat of the summer sun; new formulations are much lighter and most can be used year-round.

Freshly cut lilacs create a study in variegated shades within the grove at Katonah. We’ve left 10 to 12 inches of stem in order to adjust the height as we arrange the flowers. Normally the lilacs would be put in a bucket of water immediately after cutting. On this morning, however, Kevin was working very quickly to gather as many blooms as possible for an event, so he cut them and tossed them into the center to be gathered into water-filled buckets in the Kawasaki for transport.

HOW TO ARRANGE

CUTTING Cut lilacs right at their peak, when color and scent are strongest, or when the flowers on the cluster are one-quarter to one-half open, depending on your preference. Leave 10 to 12 inches of stem so you’ll be able to cut the lilacs down to desired heights when arranging. Be sure to put them in water immediately to preserve the blooms (if you’re picking from the garden, take a bucket of water with you). Kevin puts freshly cut lilacs in very hot water—as hot as he can get it from the tap. Hot water helps to soften the woody lilac stem and allow it to take up more water. After this initial treatment, arrange in cold water to help prevent wilting. To prep the woody branches, use your pruners to split the stem a couple of inches up the center, crosshatch with secateurs by clipping an X into the end, or crush the last few inches with a hammer or rubber mallet to help them draw more water.

MAINTAINING Lilacs are sometimes thought of as notoriously short-lived cut flowers, but the common variety can last a week or more as long as the plant is healthy. Keep arrangements out of direct light, and refresh the water every day or two. (The water will get dirty quickly, so keep an eye on it.) If you’re not able to keep up with the water replacement, as with a very large arrangement in a heavy container, at least choose a vessel that will conceal the water and stems.

ARRANGING Lilacs are excellent arrangement flowers, though not everyone thinks to take them off the bush and bring them into the home. When arranging, always use stems with vigorous foliage and fresh blooms. Strip any leaves that would sit below the waterline, but don’t discard the foliage entirely. Try retaining the leaves on the shortest stems, so that they form a bottom border of green around the lip of the vessel.

Kevin and I like to gather lilacs in two or more hues (for example, a light lavender and a dark purple) and group them by color within a vase. In a large vessel, a huge, billowing cloud of lilacs is beautiful to look at, and makes for a strikingly bold statement as a centerpiece—yet the flowers themselves are so delicate that the overall impression is of softness. To construct a large-scale arrangement like the one on this page, Kevin built an architectural foundation within the planter by using the long lilac stems themselves. The first few branches were placed almost horizontally and carefully weaved together to form a lattice as the arrangement grew. Then the remaining branches and foliage were able to nestle into the remaining spaces, building upon each other. In this way, the flowers form their own structure and support system. You can try this technique with a smaller vessel by creating a grid of tape across the top of the vase (see this page).

We place cut lilacs directly in water (top right), and Kevin uses a hammer (top left) to crush the ends of the stems (you can also use a rubber mallet, or split the stem with pruners). He removes most of the leaves; you can use them in arrangements, but they are prone to wilting quickly, so make sure to keep only the most fresh and vibrant ones. ‘Adelaide Dunbar’ (top right), ‘Sensation’ (bottom left), and ‘Beauty of Moscow’ (bottom right) have been cut for the evening’s bouquets, and will be gathered quickly to prevent wilting.

A CONVERSATION WITH

KEVIN SHARKEY

One of the great things about lilacs is that they have all these variations in so many colors, and they somehow all flatter and challenge each other equally in arrangements.

 

What are your favorite varieties?

Lilacs are one of the flowers I grew up around, so I have such a personal reference to them. There was a woman who lived down the street from us who had these deep purple, almost black lilacs—the blackest I had ever seen. It was all I could do not to steal those lilacs. Then throughout high school, I worked for the Arnold Arboretum in Boston—they are known for their lilacs—and it was there I discovered that true Wedgwood blue color; it’s just beautiful. The ones at Martha’s farm in Katonah have become my favorites.

What do you like to pair in arrangements with lilacs?

I like lilacs best on their own. But when you mix them with tulips and peonies—although it doesn’t seem as contemporary—you might think it would look vulgar, but it’s actually quite beautiful. I also love using certain foliage with lilacs, such as horse chestnut or privet leaves, and, if sturdy enough, the lilacs’ own foliage (see following image). In early spring, many plant leaves are too fragile and won’t hold up after being cut—lilac foliage included. But when you can find something hardier, like raspberry leaves, the texture and color of a green leaf is an excellent complement to the blossoms.

How do you decide on a vase?

Height and texture come into play a lot. Most of the vases that I use with lilacs are on the large side, and I tend to pick vases that are opaque, to hide the branches. I like trumpet shapes, ginger jars, or cylinders because I like to let the stems and flower heads spread out.

When shopping for lilacs, what should you look for?

I would make sure the blooms are not all fully blown—you want some buds so you know the stem is healthy and so that they can open in the vase. Although I usually like long stems, I think shorter is better if you are buying cut flowers from a store, because they have a better chance of getting water to the blossom (and of course crushing or notching the stem is key, see Cutting, this page). Hydration is especially important if they’ve been deprived of it while on display at the shop.

What are some common mistakes when arranging lilacs?

I think people sometimes miss the opportunity to celebrate the flower itself. Just keep it simple, and remember to use multiples. Lilacs aren’t meant to be treated too strictly or too quietly.

How do you make cut lilacs last longer?

Lilacs are not necessarily short-lived flowers. If they are cut from a healthy plant, they can last a full week or even longer. Generally when the flowers are from a garden, you know how fresh they are, and they are worth the cutting. When they’re from a flower market, it can get dicey. The variety can make a difference, too—I find that the common lilac lasts the longest in a vase. The more elaborate varieties, in my experience, can be more delicate—and white lilacs seem to be more susceptible to quickly wilting. Take care with the leaves—the branch structure of a lilac can be complicated and you will have to spend a lot of time removing the leaves and cleaning up the stem. If you have plenty of clean, fresh water, you don’t need flower food or chemicals to keep the arrangement looking great.

To add motion and a theatrical touch to an arrangement, Kevin mixed lilacs of deep purple with white, lavender, and bluish lavender; then, to draw the eye down from the frothy main event, he added lavender wisteria and let it trail onto the table in Martha’s servery. A flowering vine like wisteria is a bit unexpected for a flower arrangement, but the way that it cascades in a steep vertical from the cast-iron vase really captivates the eye.

When it comes to flowers, sometimes there is no such thing as “enough.” One of those times is lilac season. Take advantage of the abundance and mass the flowers in a sculptural bouquet. Using a cage-form flower frog lets some blooms (here, ‘Firmament’ and ‘Wedgwood Blue’) remain upright while others drape over the edges of this French cast-iron vase.

Combining the voluptuous blooms of the lilac with smaller, more delicate flowers and shapely foliage can produce a stunning arrangement. Here, Kevin mixed clouds of cream-colored ‘Angel White’ lilacs with the nodding white flowers of bleeding heart (Dicentra), sky-blue forget-me-nots (Myosotis sylvatica), and Persian lily (Fritillaria persica) for the subtlest hints of color. The glass vase, purchased on a trip to Australia, is comprised of fused cylinders, giving each flower breathing room.

This big, bold arrangement for the living room at Skylands offers a stunning centerpiece for the table. Several shades of lilac are combined, some in full bloom and others in bud, which adds texture to the display. A lattice-like weave of branches holds the lilacs together (see Arranging, this page) so that the individual stems stay in place and build height. “Very few flowers can go from a painted wrought-iron trumpet to a gold china vase to clear glass, ceramic, or even, as here, cement,” says Kevin. “It just goes to show you how versatile lilacs can be in terms of playing with other materials.” Don’t shy away from lilacs at a dinner party: “There are a lot of flowers that have such a heavy aroma that you wouldn’t want to eat with them nearby,” says Kevin. “But lilacs, although they have a fragrance, are certainly welcome at the table.”

Just as masses of lilacs can perform in a large arrangement, a solitary bloom or a few stems work beautifully in small vessels, such as a pair of gold vermeil vases (a Mother’s Day gift from Kevin). “The blossoms are particularly compatible with vessels that have a strong visual point of view, like gold.” A matching set makes a dynamic duo, as an alternative to a larger, singular display. ‘Sensation’ lilacs are studded with airy green hellebore, placed one at a time into the spaces left by the lilac stems.

A large and shapely Astilboides tabularis leaf can make a big statement, adding asymmetry and dimension to this arrangement dominated by ‘Adelaide Dunbar’ lilac florets. Placing the earthenware pot on a pedestal of wood adds another layer of visual impact. Try positioning a vase on a decorative plate or tray to boost the scale of your arrangement.